This invention relates to the attenuation of power oscillations in a network fed by a synchronous generator in general and more particularly to an improved circuit arrangement for bringing about such attenuation.
In order to attenuate power oscillations in networks by acting upon the exciter of a synchronous generator it has previously been customary to use circuits which are designed for a certain limited frequency range. These circuits, within their designed frequency range, form a damping signal which is derived from power changes in a network. The signal acts on the exciter of at least one synchronous machine which is connected to the network so as to influence the voltage regulator in a direction to eliminate the effects of power change. When filters are used, the damping signal has, within the selected range, an optimum phase position for only a single oscillation frequency. Where a range of oscillation frequencies are present, as is generally the case in operation of such devices, in order to obtain optimum phase positioning over the entire range, a plurality of differently rated filters thus becomes necessary. To use such a plurality of filters results in undue expense and can lead to undesired interactions.